Anti-stall device or dash-pot



Dec. 2, 1958 J. R. EMERSON 2,862,702

ANTI-STALL mzvxcs OR DASH-POT 2 Sheets-Sheet 1 Filed Oct. 25, 1955 Fig./' 2

John R. E mersan- .IBY

INVENTOR.

Deb. 2, 1958 J. R. EMERSON ANTI-STALL DEVICE OR DASH-POT Filed Oct. 23, 1953 2 Sheets-Sheet 2 I 8.? Fig.6

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John R. E mersan 1N VEN TOR. m BY flu United States. PatentQ ANTI-STALL DEVICE OR DASH-POT John R. Emerson, Flint, Mich., assignor to Fuller &

Emerson Manufacturing Co., Flint, Micln, a copartnership 7 Application October 23, 1953, Serial No. 388,020 I 15 Claims. 01. 267-1) r Other objects and advantages which will become sub-' sequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a longitudinal section taken through a dash-pot constructed in accordance with this invention;

Figure 2 is a transverse sectional view taken substantially along the plane of section line 22 in Figure 1;

Figure 3 is an enlarged perspective view of the spindle assembly;

Figure 4 is an enlarged perspective View of the guide bushing;

Figure 5 is a plan view of a retaining washer utilized in this invention; and

Figure 6 is a longitudinal section taken through a modified form of the invention;

Figure 7 is an enlarged section showing the manner of connection between the spindle and cup in Figure 6;

Figure 8 is a longitudinal section taken through a still further modified form of the invention; and

Figure 9 is a plan view of the cup retaining washer:

utilized in Figure 8.

Referring now more particularly to Figure 1, the reference numeral 10 indicates generally a bracket of a vehicle or the like and the reference character 12 indicates generally a mounting bolt having a threaded end portion 14' threadedly received within a suitable boss 16 on the bracket and the reference character 18 indicates a lock nut for securely fastening this bolt thereto.

Reference character 20 indicates generally the casing forming the main portion of'the dash-pot assembly and which is composed of two half sections 22 and 24 each having a radial flange portion 26 and 28, respectively;

the latter of which is crimped over against the former in the manner shown for securing the two casing halves together and for securing therebetween the outer peripheral edge of a resilient annular'washer member 30. The outer end of the section 22 receives the head 32 of the bolt assembly 12 and is crimped therearound and suitably staked as indicated by the reference character 34 to'form a fluid tight seal therewith. In this manner, it will be manifest'that the assembly may be thus conveniently secured to the bracket of an associated vehicle, although it is to be understood that other forms of fastening means may be utilized without departing from the spiritof the hereinafter described dash-pot assembly.

The washer or gasket 30 forms a portion of the mov- 2,862,702 Patented Dec. 2,1958

able wall assembly which subdivides the interior ofthe casing 20 into two separate chambers. The inner periphery of the gasket 30 is provided with a thickened rim portion 36 which seats around the portion of the cup member 38 which, in conjunction with this gasket, forms a complete movable wall assembly. The engagement between the washer 30 and the cup member 38 is such that the two engage in sealing contact with the inner periphery of the washer 30 engaging against the wall or shoulder portion 40 of the cup and it will be noted that the star washer member 42 positively maintains contact between the portion 36 and the cup member 38. As seen most clearly in Figure 5, the star washer 42 is provided with notched portions 44 on its inner circumference and'its inner edge 46 is slightly beveled to effect deformation of the washer when assembled on the cup member such that it frictionally engages thereon for positively maintaining the proper relationship between the washer 30 and the cup 38.

A spindle member indicated generally by the reference character 46 has its inner end portion projecting within the casing 20 and its inner extremity is of reduced diameter for free and loose reception within the central belled aperture 48 formed in the cup member 38. The intermediate or shank portion 50 of the spindle is provided with a tapered shoulder 52 at the juncture with the reduced end portion 54 and this shoulder is provided with a groove or notched portion, the purpose of which willbe presently apparent. The outer'end wall 58 mitting fluid to pass between the bushing and spindle. Thebushing 60 is preferably formed of nylon or other suitable material and is pressed in placei I A resilient protective cup indicatedgenerally'by the reference character 62 is fitted' over the outer end of the spindle member 46 and has the thickened'portion 64- of its outer end wall received within a circumferential groove' 66 formed adjacent thefree end of the spindle 46'. The

inner end of the protective cup 62 is flanged inwardly as indicated by the reference character 68 and seats against the previously described end wall 58 of the casing'section 24 such as to provide a dirt seal therebetween. A conical spring 70 seats respectively between theinner surfaces of the flange 68 and the end wall portion 64 of the pro-' tective cup such as to urge these portions into sealing engagement with the end wall 58 and the forward end of the spindle respectively and to normally urge the spindleto the right in Figure 'l. such'that the spring assumes the position shown. In thisrespect, it will be-noted that the inner free end of the spindle 46is 'circumferentially grooved as at 72 and receives' therein a C-shap'edabut ment washer or stop member 74 which-engages against the rim of the belled end of the cup member 38. It will be further noted that the-positioning ofthe abutment member 74'is such that when it -is in engagement with the cup member .38, the. shoulder 52 .of the spindle is out.

of engagement therewith.

The outer free end of the spindle member 461's adapted to be engaged by a portion of the accelerator linkage or carburetor lever of an internal combustion engine as indicated generally by the dotted line '76. It is to be understood that'the linkage of the accelerator system of the vehicle is normally provided with sufficient resilient mechanism to normally compress the spring 70 of the dash-pot assembly and force the spindle 46 to the 'leftin Figure 1. such that the spindle isat its extremityfof posi;

tion in this direction. y

In operation, during normal throttle control conditions of the internal combustion engine, the accelerator linkage portion 76 will be out of engagement with the spindle 46 such that the spindle may assume the position shown in Figure l with a portion of the cup member 38 against and in contact with the casing Section 24., When; the accelerator; linkage is released, the member 76 will spring rapidly backward to a position; striking the spindle 46 such that this member is urged leftward in Figure l'to such a distance as to engage it-s shoulder 52 against the belled portion of the cup member 38 surrounding its central opening. The shoulder 52 then is in sealing contact with the cup member 38 such that air within the chamber to the left in Figure 1 is. metered slowly to; the right hand chamber through the metered notch or orifice 56. As soon as the acceleratorlinkage is normally again engaged for opening the throttle of the engine, the spring 70 will force, the spindle 46 to the right in Figure 1 such that, the abutment washer 74 engages the cup member 38'permitting free passage of fluid from the right hand chamber to the left hand chamber such that the spindle member may rapidly assume its normal position or right hand position, as shown in Figure 1.

It is pointed out that the right hand chamber formed between the movable wall assembly and the casing section 24 taken in conjunction with the interior of the protective cup member 62 normally forms a relatively fluid-tight chamber. That is, the purpose of the particular construction shown, especially the protective cup, is to minimize leakage of air into and out of the above mentioned chamber. Whereas it will be apparent that slight leakage of air into and out of the chamber is possible, to thus allow the air within the chamber to match the density of the ambient air, the flexibility of the relatively thin peripheral side wall of the protective cup permits this member to breath in accordance with'movement of the movable wall assembly, minimizing air leakage and hence entry of dirt or other foreign material into the dash-pot assembly. This feature is important inasmuch as it materially lengthens the life of the dashpot assembly by reducing undue abrasive action to a minimum. Also the light engagement between the protective cup and the casing section 24 is not such as to cause these portions to set or stick together during normal operating conditions. v

Referring now more particularly to Figure 6 wherein a modified form of the invention is illustrated, it will be noted that the casing 78, annular washer member 80, and resilient cup 82 are constructed in the same manner as corresponding elements of the form of the invention shown in Figure 1. Likewise, the cup member 84 is structurally similar to the cup member 38 previously described with the exception that the neck 86 thereof defining its central opening is coined, staked or otherwise suitably secured to the reduced inner end portion of the spindle 88 with the neck in engagement with spindle shoulder 90. This shoulder is provided with a metering notch 92 to provide a. permanent interconnecting passage between the chambers existing on opposite side of the washer wall member 80.

A- conical spring member 94 has the coil 95 formed at its small end engaged within a groove 96 in the spindle in the manner shown most closely in Figure 7. The large end of the spring either lightly engages against the inner rim 98 of the washer member 80 or has slight clearance all the way around in order to keep this rim in close proximity to the stepped face 100 of cup member 84.

When the accelerator, pedal is released, the spindle 88 is abutted to move it to the left in Figure 6 so that the rim 98 under the action of spring 94 taken in conjunction with the higher pressure existing within the left-hand chamber will sealingly engage the cup member and effect the dash-pot action of the device by forcing the fluid transfer between chambers to take place through the metering notch 92, thus delaying the closing of the carburetor throttle valve. When the accelerator pedal is again depressed, the assembly will rapidly return to the position shown in Figure 6 inasmuch as fluid will flow from the right-hand to the left-hand chambers not only through the metering notch but between the washer member and cup member 84 since the pressure within the right-hand chamber will overcome the force of spring 94 and permit the rim of the washer member to separate from contact with the stepped face 100. In this respect, it will be noted that the diameter of the washer member opening is greater than the diameter of the cylindrical portion 102 of the cup member which it surrounds.

Referring now tov Figure 8 wherein a still further modified form of the invention isdisclosed, the sole distinction between this form and that illustrated in Figure 6 is the substitution of a stop washer 104 to replace the spring 94. The stop washer is provided with notches 106 in its, inner edge and this edge, is slightly beveled to'elfect deformation of the washer, when assembled on the. spindle, whereby it is securely held thereon.

In this latter form of the invention, movement of'the. spindle 108 to the right in Figure 8 will permit the inner rim 110 of washer member 112 to unseat from the stepped face 114 of cup member 116, it being limited in its movement by the stop washer 104 Movement in the opposite direction will, of course, be: retarded since the rim of the washer member will seal against the associated face on the cup member, permitting, fluid transfer only through the metering notch 118.

From the foregoing, the construction and operation of the device. will be readily understood and further explanation is believed to be unnecessary. However, since, numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the.

invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope. of the appended claims.

What is claimed as new is as follows:

l. A dashpot assembly comprising a casing having. opposed end walls, one of which is apertured for guidably receiving a spindle within the casing, a. movable Wall dividing the interior of said casing into two separate end chambers, said wall having a rigid central portion provided with a belled opening, said spindle having a reduced end portion received in the opening and. having a tapered shoulder engageable with that part of the rigid central portion bounding the opening, When the spindle is moved in one axial direction, said shoulder being longitudinally grooved to provide a limited passage of fluid between the chambers upon movement of the spindle in said one direction, abutment means provided on the free end of said spindle permitting movement of said shoulder away from said. rigid central portion when the spindle is moved in the other direction and permitting free passage of fluid between said chambers upon movement of the spindle in said other direction.

2. A dash-pot assembly comprising a casing having opposed end Walls, one of which is apertured for guidably receiving a spindle within the casing, a movable wall dividing the interior of said easing into two separate end chambers, said wall having a rigid central portion provided with a belled opening, said spindle having a reduced end portion freely received in theopening and having a tapered shoulder engageable with that part of the rigid central portion bounding the opening, when the spindle is moved in one axial direction, said shoulder being longitudinally grooved to provide a limited passage of fluid between the chambers upon movement of the spindle in said. one direction, abutment means provided on the free end of said spindle permitting movement of said shoulder away from said rigid central portion when the spindle is moved in the other direction and permitting free passage of fluid between said chambers upon movement of the viding the interior of said easing into two separate end chambers, said wall having a rigid central portion provided with a belled opening, said spindle having a reduced end portion freely received in the opening and having a tapered shoulder engageable with that part of the rigid central portion bounding the opening, when the spindle is moved in one axial direction, said shoulder being longitudinally-grooved to provide a limited passage of fluid between the chambers upon movement of the spindle in said one direction, abutment means provided on the free end of said spindle permitting movement of said shoulder away from said rigid central portion when the spindle is moved in theother direction whereby to permit free passage of fluid between said chambers upon movement of the spindle in said other direction, and a protective cup carried on the projecting end of said spindle in relatively fluid-tight contact with said casing, said cup being resilient such as to breathe and form a fluid reservoir upon movement of said movable wall, whereby to prevent entry of foreign material within the casing.

4. A dash-pot assembly comprising a casing having opposed end walls, one of which is apertured for guidably receiving a spindle within the casing, a movable wall dividing the interior of said easing into two separate end chambers, said wall having a rigid central portion pro-' vided with a belledopening, said spindle having a reduced end portion freely received in the opening and having a tapered shoulder engageable with that part of the rigid central portion bounding. the opening, when the spindle is moved in one axial direction, said shoulder being longitudinally grooved to provide a limited passage of fluid between the chambers upon movement of the spindle in. said one direction, abutment means provided on the free end of said spindle permitting movement of said shoulder away from said rigid central portion when the spindle is moved .in the other direction whereby to permit free passage of fluid between said chambers upon movement-of the spindle in said other direction, means for normally urging said spindle in said other direction, and a protective cup carried on the projecting end of said spindle in relatively fluid-tight contact with said casing, said cup being resilient such as to breathe and form a fluid reservoir upon movement of said movable wall, whereby to prevent entry of foreign material within the casing.

5. A dash-pot assembly comprising a casing having opposed end walls, one of which is apertured for guidably receiving a spindle within the casing, a movable wall dividing the interior of said easing into two separate end chambers, said wall having a rigid central portion secured to said spindle and a flexible peripheral portion overlapping the central portion, said spindle having a groove extending on opposite sides of said wall to permit a limited passage of fluid between the chambers in one axial direc-' tion of movement of said spindle, said central and peripheral portions of the wall being separable, when the spindle is moved axially in the other direction, to permit free passage of fluid between the chambers.

6. A dash-pot assembly comprising a casing having opposed end Walls, one of which is apertured for guidably receiving a spindle within the casing, a movable wall dividing the interior of said easing into two separate end chambers, said wall having a rigid central portion secured to said spindle and a flexible peripheral portion overlapping the central portion, said spindle having a groove extending on opposite sides of said wall to permit a limited passage of fluid between the chambers in one axial direction of movement of said spindle, said central and peripheral portions of the wall being separable, when the spindle is moved axially in the other direction, to permit free passage of fluid between the chambers, and means for yieldingly resisting the separation of the overlapping portions of said wall.

7. A dash-pot assembly comprising a casing having opposed end walls, one of which is apertured for guidably receiving a spindle within the casing, a movable wall dividing the interior of said easing into two separate end chambers, said wall having a rigid central portion secured to saidspindle and a flexible peripheral portion overlapping the central portion, said spindle having a groove extending on opposite sides of said wall to permit a limited passage of fluid between the chambers in one axial direction of movement of said spindle, said central and peripheral portions of the wall being separable, when the spindle is moved axially in'the other direction, to permit free passage of fluid between the chambers,-and means for yieldingly resisting the separation of the overlapping portions of said wall, said means comprising a spring member secured to said spindle and engaging the inner rim of said peripheral wall portion.

8. A dash-pot assembly comprising a casing having opposed end walls, oneof which is apertured for guidably receiving a spindle within the casing, a movable wall dividing the interior of said easing into two separate end chambers, said wall having a rigid central portion secured to said spindle and a flexible peripheral portion overlapping the central portion, said spindle having a groove extending on opposite sides of said wall to permit a limited passage of fluid between the chambers in slidably received in said bushing, a movable wall dividing' the interior of said easing into two separate end chambers,- said wall having a rigid central portion provided with a:

belled opening, said spindle having a reduced end portion freely received in the opening and having a tapered shoulder engageable with that part of the rigid central portion bounding the opening, when the spindle is moved in one axial direction, said shoulder being longitudinally grooved to provide a limited passage of fluid between the chambers upon movement of the spindle in said one direction, abutment means provided on the free end of said spindle permitting movement of said shoulder away from said rigid central portion when the spindle is moved in the other direction whereby to permit free passage of fluid between said chambers upon movement of the spindle in said other direction.

10. A dash-pot assembly comprising a casing having opposed end walls, one of said end walls having an aperture, a bushing secured in said aperture, a spindle slidably received in said bushing, a movable wall dividing the interior of said casing into two separate end chambers, said wall having a rigid central portion secured to said spindle and a flexible peripheral portion overlapping the central position, said spindle having a groove extending on opposite sides of said wall to permit a limited passage of fluid between the chambers in one axial direction of movement of said spindle, said central and peripheral portions of the wall being separable, when the spindle is moved axially in the other direction, to permit free passage of fluid between the chamber.

11. A'dash-pot assembly comprising a casing having opposed end walls, a spindle having an inner end and an outer end, one of said walls having an aperture guidably receiving said spindle with its inner end in the casing and its outer end ,exteriorly of the casing, a wall .dividing the interior of the easing into two chambers,

said wall having a rigid central portion connected with the inner end of said spindle and a flexible peripheral portion secured to the casing and" overlapping the central portion, means presenting a restricted orifice communicating said chambers, said central and peripheral portions of the wall being separable when the spindle is moved axially in one direction to permit free passage of fluid between the chambers.

12. A dash-pot assembly comprising a casing having opposed end walls, a spindle, one wall having an aperture guidably receiving the inner end of said spindle within the casing, a wall dividing the interior of the casing into two chambers, said wall having a rigid central portion connected with the inner end of said spindle and a flexible peripheral portion secured to the casing and overlapping the central portion, means presenting a restricted orifice communicating said chambers, said centraland peripheral portions of the wall being separable when the spindle is moved axially in one direction to permit free passage of fluid between the chambers, a-

resilient member carried by the outer end of said' spindle, said resilient member defining a chamber communicating with one of the chambers within said casing and having opposite annular end walls, one of which is engaged upon said spindle and the other of which is engaged against the outer surface of said casing, and a spring within said resilient'member engaged with said end walls of said resilent member for normally urging said spindle in the other axial direction.

13. A dash-pot assembly comprising a casing having opposed end walls, a spindle having an inner and an. outer end, one of said walls having an aperture guidably receiving said spindle with its inner end in the casing and its outer end exteriorly of the casing, a wall dividing the interior of the casing into two chambers, said wall having a rigid central portion connected with the inner end of said spindle and a flexible peripheral portion secured to the casing and overlapping the centralporti'on, means presenting a restricted orifice in said spindle communicating said chambers, said central and peripheral portions of the wall being separable when thespindle is moved axially in one direction to permit free passage of fluid between the chambers, said rigid central portion of the wall having a cylindrical portion and a stepped of the wall having a thickened inner rim portion disposed.

on said stepped face and spaced radially from said cylindrical part of the central wall portion, the remaining portion of the peripheral wall portion being more flexible than the inner rirn' thereof whereby deformation of the inner rim to close about the cylindrical portion is obviated;

14. The dash-pot assembly of claim 12 wherein said spindle has a circumferential groove near its outer end and providing a shoulder in said spindle on which one wall of said member seats.

1.5. A dash-pot assembly comprising a casing having opposed end walls, one of which is apertured for guidingly receiving a' spindle Within the casing, a movable wall dividing the interior of said casing into two separate end chambers, said wall having a rigid central portion provided with a belled opening, a spindle having a reduced end portion received in the opening and having a tapered shoulder engageable with that part of the rigid central portion bounding the opening, when said spindle is moved in one axial direction, said shoulder being longitudinally grooved to provide a limited passage of fluid between the chambers upon movement of the spindle in said one direction.

References Cited in the file of this patent UNITED STATES PATENTS 456,016 Canet, July 14, 1891 1,564,554 Gifiord Dec. 8, 1925 1,992,555 Templin Feb. 26, 1935 2,115,383 Christensen April 26, 1938 2,387,066 Harding Oct. 16, 1945 2,489,381 Lindahl Nov. 29, 1949 2,564,394 Cole Aug. 14, 1951 2,657,037 Braun Oct. 27, 1953 2,657,038 Emerson Oct. 27, 1953 2,680,610 Harry June 8, 1954 2,712,440 Crabtree et al July 5, 1955 FOREIGN PATENTS 849,044 Germany Sept. 11, 1952 

